# NTSB ANC07CA053: Grumman G21A, N7811, Dutch Harbor, AK, June 24, 2007 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: June 24, 2007, 15:00 local (23:00 UTC) - Place: Dutch Harbor, AK - Coordinates: 53.971942, -166.850006 - Nearby events: https://openairdocs.org/map.md?lat=53.9719&lon=-166.8500&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report August 30, 2007 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - NTSB case key (mKey): 66187 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC07CA053 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/66187/pdf - Page: https://openairdocs.org/ntsb/ANC07CA053 ## Probable cause The pilot's inadequate compensation for wind conditions during the takeoff roll, which resulted in a loss of directional control and a nose over. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - on ground/water, takeoff - roll/run - compensation for wind conditions - inadequate, pilot in command (cause) - On ground/water encounter with terrain/water, takeoff - roll/run - terrain condition - tundra - Nose over, takeoff - roll/run ## Analysis The pilot had dropped off passengers, and was taking off to return to the base airport under Title 14, CFR Part 91, when the accident occurred. The pilot said he was departing on a hard surface runway in an amphibious, tailwheel equipped airplane. He said after the tailwheel lifted off, he believed a quartering gust of tailwind pushed the airplane off the runway. He said he tried to maintain directional control, but the airplane's right main landing gear encountered a tundra mound, and the airplane nosed over. The pilot said the right wing separated from the airplane during the accident. There were no known mechanical anomalies with the airplane prior to the accident. ## Factual narrative The pilot had dropped off passengers, and was taking off to return to the base airport under Title 14, CFR Part 91, when the accident occurred. The pilot said he was departing on a hard surface runway in an amphibious, tailwheel equipped airplane. He said after the tailwheel lifted off, he believed a quartering gust of tailwind pushed the airplane off the runway. He said he tried to maintain directional control, but the airplane's right main landing gear encountered a tundra mound, and the airplane nosed over. The pilot said the right wing separated from the airplane during the accident. There were no known mechanical anomalies with the airplane prior to the accident. ## Aircraft - Registration: [N7811](https://openairdocs.org/aircraft/N7811), registered now, S/N B-122, built 1942 (OpenAirDocs) - Reported make and model: Grumman G21A - Registry model: [Grumman G-21A](https://openairdocs.org/model/grumman-g-21a) (registry code 3951204) (OpenAirDocs) - Registry engine: [Pratt & Whitney R-985 series](https://openairdocs.org/engine/pratt-whitney-r-985-series) (registry code 52008, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: B-122 - Airframe hours: 17294 - Engines: Covington R-985-AN-14B 450 horsepower reciprocating - Damage: Substantial damage - Flight: Positioning, Part 91 - Registered owner: Peninsula Airways Inc - Airworthiness certificate: Standard, Normal - Last inspection: AAIP, June 1, 2007 - Departed: DFB, Dutch Harbor, AK - Destination: DUT, Dutch Harbor, AK - Flight plan: VFR - Airport: DFB, Driftwood Bay, runway 30, gravel ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 50; injuries: none; airline transport; airplane ratings: single-engine land, multi-engine land, single-engine sea, multi-engine sea; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review March 1, 2007; seat: left; flight hours: 10,650 total, 1,350 in this make and model, 80 in the last 90 days, 30 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 270° at 15 knots, gusting 20 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 57 °F, dew point 46 °F - Altimeter: 29.95 inHg ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20070624012999A](https://openairdocs.org/incident/20070624012999A), Jun 24, 2007: Grumav G21A, Dutch Harbor, AK, Substantial damage. (-23) Received a written statement from the airman with the following information: during the takeoff roll with the tail in the air, I believe we got a rough… ## Other investigations on N7811 (1) From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. - [NTSB ANC90LA102](https://openairdocs.org/ntsb/ANC90LA102), Jun 30, 1990: Grumman G21 (N7811), King Salmon, AK, substantial damage. Probable cause: THE PILOT FAILED TO ADEQUATELY COMPENSATE FOR THE PREVAILING WIND CONDITIONS AND HIS FAILURE TO MAINTAIN DIRECTIONAL CONTROL. A CONTRIBUTING FACTOR WAS THE STRONG CROSSWIND COMPONENT. From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.